Approximately half of all adults in the United States have a chronic health condition and many of those adults are prescribed medication for disease management. An estimated 20 to 60% of US adults do not adhere to their prescribed medication. Nonadherence can have significant negative health effects for the individual and contribute to increases in hospitalization, healthcare costs, and mortality. Adherence is a complex issue, but cost and affordability of medication is a common and critical barrier. Cost-related nonadherence (cost-coping) includes behaviors such as not filling or re-filling a prescription, filling some prescriptions but not others, intentionally skipping doses, or reducing the dose to save money, and is reported by an estimated 10-30% of adults. People who report cost-coping related to medication adherence also tend to report other cost-coping actions including reducing spending on food and utilities, borrowing money to afford medical care, or putting expenses on credit. While we know risk factors for cost-related nonadherence, we do not know how patients make choices about which bills to pay, which prescriptions to fill, and what to do when they cannot afford medication. We also do not know if or how healthcare providers address cost-related nonadherence. Our long- term objective is to deliver interventions to reduce cost-related nonadherence. Our short-term objective is to identify how patients and healthcare providers approach affordability and adherence and use those data to refine and pilot test an intervention promoting patient-provider discussion about cost, affordability, and adherence. Our Specific Aims are: (1) Identify the range of financial demands, prioritization, and adherence choices by low-income individuals faced with chronic disease. (2) Determine whether providers have cost- conversations with their patients, how they approach cost-related nonadherence in their patient population, and their awareness of financial resources for low-income patients. (3) Develop and pilot test an intervention to increase cost-conversations between patients at-risk for cost related nonadherence and their providers. We will achieve these aims through in-depth individual interviews with patients and key informant interviews with various healthcare providers. We will then develop a patient-provider intervention aimed at reducing cost- related nonadherence that will be feasibility tested in Aim 3. Several factors make this project innovative including our mixed method and multi-level research design and our acknowledgement that adherence varies over time and across medications. This work is significant because of the extent and impact of cost-related nonadherence and the potential for substantial improvement in health outcomes with successful intervention. This study steps beyond previous research on the correlates of cost-related nonadherence, and delves deeper into the context of adherence choices, leading to a patient-centric intervention to promote cost-conversations with providers. These findings can be broadly generalized across other areas of prevention, management and treatment of disease such as adherence to screening, testing, or self-management for chronic disease.